89 TO 01 ENGINE SWAP

[JH4020]

New to this, just bought my first MJ. My question, can you swap the drive train from a 2001 XJ to a 1989 Mj?

[onlyinajeep726]

Anything is possible with enough know-how and motivation.

 

Question is, are you going to be using the '89's engine harness and computer, or are you talking everything from the '01?  If the latter, you're going to have to swap the dash and corresponding harnesses since everything is completely and totally different between the two eras.  In addition, you're going to have to figure out how to make a fuel pump work since the '01 XJ uses a plastic tank with a returnless fuel sender.  There's a LOT of swapping and modification to do if you want to use everything from the '01.

 

The good news is, the drive train will physically bolt in place. :yes:

[JH4020]

Is there a tank I can get for the my?

[onlyinajeep726]

Later model Dodge Dakota plastic tanks have been modded to fit.  Not sure what is necessary to make it work.  I'm sure others will chime in.

[shelbyluvv]

http://comancheclub.com/topic/30671-97-swap-how-to/

[JH4020]

My MJ is an 89. With that being said what newer year models can I go to for the drive train and interior for an up-grade to get rid of the Renix? Any help would be greatly appreciated.

[teamsmith]

My MJ is an 89. With that being said what newer year models can I go to for the drive train and interior for an up-grade to get rid of the Renix? Any help would be greatly appreciated.

Is this Justin from Opposite Lock? http://oppositelock.kinja.com/pulled-the-trigger-1744089522 

I just read your article. Welcome to the club. 

 

Why do you want to get rid of the Renix? Is there a problem or do you just see the rudamentary FI and vaccuum lines as potentials for headaches? FWIW, I plugged off all of my vacuum lines and removed my EGR.

 

To answer your question:  You can swap to OBDII with full harness, engine, flywheel, computer, and dash swap from a 97+ XJ (2 door or 4 door) but it's a real pain to fit the 97+ dash in. Any XJ or MJ from 91-96 is OBDI and but will still require a harness, computer, and flywheel swap. If you have a donor vehicle it's best to leave everything in it and swap over one piece at a time. 

 

A 2001 engine can't be swapped in without doing a full harness, fuses, the whole nine. Reason is ignition coil packs in the 2001 vs. the single ignitiion coil in 2000 and prior. 

[JH4020]

I found a 93Xj with low miles cheap. My plan was for me to swap everything over after I take the MJ down to body and frame. Once I have that all cleaned up and painted then was going to move everything over. Still in the pondering stage.

[onlyinajeep726]

I found a 93Xj with low miles cheap. My plan was for me to swap everything over after I take the MJ down to body and frame. Once I have that all cleaned up and painted then was going to move everything over. Still in the pondering stage.

 

This would be a much easier swap, for sure.

[JH4020]

Will there be any firewall mods needed? What about fuel tank or any other surprises?

[shelbyluvv]

It will be a bolt in. You will need to source a HO era MJ fuel sender for the gauge to read correctly.

[onlyinajeep726]

It will be a bolt in. You will need to source a HO era MJ fuel sender for the gauge to read correctly.

 

I have one, hehe. :brows:

[JH4020]

Thanks for all the help. I'm picking up a 92 XJ to do the swap. Hopefully it will go as expected.

[onlyinajeep726]

Thanks for all the help. I'm picking up a 92 XJ to do the swap. Hopefully it will go as expected.

 

You'll still need a HO fuel sender.  The XJ's are not compatible with MJ's tank unless you can modify it.  Otherwise, it should be a straightforward swap.

[JH4020]

What newer year model xj motors will work with my 89 mj automatic?

[onlyinajeep726]

Any 4.0 from '87-'99 can be made to work relatively easily. 

 

Cruiser’s HO into Renix Swap

This swap is easier than some will lead you to believe, generally those who have never done it. Those of us who have done it, like myself, will share with you the things that need to be done for a successful swap. Just think of it as swapping in a long block.

The HO and Renix have some differences but none that can’t be overcome very easily.

Any HO engine from an XJ or ZJ through 1999 can be used. One running change was that the rear of the head was no longer drilled and tapped for the temperature gauge sender beginning in the 96 model year. The sender can be relocated to the threaded hole in the thermostat housing taken from the HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head for the sender.

You will be using the intake and exhaust manifolds from your Renix, along with all your sensors and wiring. Since the intake ports of the HO are slightly different, you use the Renix gasket. Exhaust ports are identical.
You will need to use your Renix distributor as it is different than the HO because they use different fuel management systems. The flywheel or flexplate from the Renix must be used so your CPS gets the correct signals. The valve cover from the Renix allows you to keep your CCV system intact and requires no modifications.

The HO block will have a plug in the coolant galley on the driver’s side of the block, closest to the front, which needs to be removed so your Coolant Temp Sensor can be installed in it’s place just as it is on the Renix. It requires a 5/16” square drive or a modified 3/8” drive that has been ground down to fit. Do this before installing the engine.

As for the knock sensor, which is located just above the oil pan on the driver’s side of the engine about mid way, all the blocks I’ve seen are threaded for it. If not, I’ve heard they may be drilled but not tapped. Tap the hole if that’s the case.


Revised 03/28/13

[cruiser54]

 

Any 4.0 from '87-'99 can be made to work relatively easily. 

 

Cruiser’s HO into Renix Swap

 

This swap is easier than some will lead you to believe, generally those who have never done it. Those of us who have done it, like myself, will share with you the things that need to be done for a successful swap. Just think of it as swapping in a long block.

 

The HO and Renix have some differences but none that can’t be overcome very easily.

 

Any HO engine from an XJ or ZJ through 1999 can be used. One running change was that the rear of the head was no longer drilled and tapped for the temperature gauge sender beginning in the 96 model year. The sender can be relocated to the threaded hole in the thermostat housing taken from the HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head for the sender.

 

You will be using the intake and exhaust manifolds from your Renix, along with all your sensors and wiring. Since the intake ports of the HO are slightly different, you use the Renix gasket. Exhaust ports are identical.

You will need to use your Renix distributor as it is different than the HO because they use different fuel management systems. The flywheel or flexplate from the Renix must be used so your CPS gets the correct signals. The valve cover from the Renix allows you to keep your CCV system intact and requires no modifications.

 

The HO block will have a plug in the coolant galley on the driver’s side of the block, closest to the front, which needs to be removed so your Coolant Temp Sensor can be installed in it’s place just as it is on the Renix. It requires a 5/16” square drive or a modified 3/8” drive that has been ground down to fit. Do this before installing the engine.

 

As for the knock sensor, which is located just above the oil pan on the driver’s side of the engine about mid way, all the blocks I’ve seen are threaded for it. If not, I’ve heard they may be drilled but not tapped. Tap the hole if that’s the case.

 

 

Revised 03/28/13

 

Thanks for posting that for him!! 

 

I've got Tip #28 written and published here on CC and also on my website. Tip 29 and 30 in the works. Tip 1 has an addition in the Comanche section at the end thanks to Hornbrod. 

[JH4020]

My plan is to swap a newer 91 to 96 XJ motor,harness,dash,everything to my trans, trans case, and axles for now. Will any of the above engines attach to my MJ?

[cruiser54]

My plan is to swap a newer 91 to 96 XJ motor,harness,dash,everything to my trans, trans case, and axles for now. Will any of the above engines attach to my MJ?

Yep.

[JH4020]

Well, the 92 XJ sold on me, so now I am looking at a 94. Everything still the same, including the MJ HO sending unit?

[gogmorgo]

Nothing significant. With minimal research (five nmminutes with google) I was able to overcome them all. In swapping a '93 motor, trans, and tcase into my '91, these are the differences I remember:

CPS has a different connector. I just swapped the harness side across from the XJ to my MJ, matching wire colours, and it worked just fine.

Oil pressure sender was different. The one from my '91 was a direct swap.

Speedometer gear assembly is different. The one from my '91 was a direct swap.

The tcase harness didn't quite work. My memory's a little foggy here, but I think it had to do with the '91 being a 231 with the CAD, and the '93 being a 242 without cad. I was able to somehow combine the two to make for a direct swap with fully-functioning shift lights, just don't remember exactly what I did there. I don't remember having spliced wires, but I do remember cutting them off, I think the ones that ran to the CAD (I already had a one-piece shaft in it).

[JH4020]

My plan is to move everything from the XJ to the MJ.

[gogmorgo]

Then you should have everything you need.

[JH4020]

What about the fuel pump?

[onlyinajeep726]

You'll still need an HO era MJ specific fuel sending unit.  Any XJ you use for the swap that is between a '91-'95, will need that sending unit.  Those years (in the XJ's) still have a return fuel line on the injector rail.  '96+ XJ's use a returnless system, something that was never implemented in the MJ's.  As I mentioned before, I have a sending unit from a '91 that is in great shape that I may be persuaded to sell if you (or anyone) is in need.